From: Thierry Reding treding@nvidia.com
The semantics of do_div() are (see include/asm-generic/do_div.h):
uint32_t do_div(uint64_t *n, uint32_t base)
Using a different type will therefore cause the following warning (as seen on xtensa/allmodconfig):
CC [M] drivers/gpu/drm/mgag200/mgag200_mode.o In file included from arch/xtensa/include/generated/asm/div64.h:1:0, from include/linux/kernel.h:124, from include/linux/delay.h:10, from drivers/gpu/drm/mgag200/mgag200_mode.c:14: drivers/gpu/drm/mgag200/mgag200_mode.c: In function 'mga_vga_calculate_mode_bandwidth': include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ ^ drivers/gpu/drm/mgag200/mgag200_mode.c:1471:2: note: in expansion of macro 'do_div' do_div(pixels_per_second, total_area); ^ include/asm-generic/div64.h:43:28: warning: comparison of distinct pointer types lacks a cast (void)(((typeof((n)) *)0) == ((uint64_t *)0)); \ ^ drivers/gpu/drm/mgag200/mgag200_mode.c:1474:2: note: in expansion of macro 'do_div' do_div(bandwidth, divisor); ^
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/mgag200/mgag200_mode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c index 83485ab81ce8..4d519dc99db8 100644 --- a/drivers/gpu/drm/mgag200/mgag200_mode.c +++ b/drivers/gpu/drm/mgag200/mgag200_mode.c @@ -1455,9 +1455,9 @@ static int mga_vga_get_modes(struct drm_connector *connector) static uint32_t mga_vga_calculate_mode_bandwidth(struct drm_display_mode *mode, int bits_per_pixel) { - uint32_t total_area, divisor; - int64_t active_area, pixels_per_second, bandwidth; uint64_t bytes_per_pixel = (bits_per_pixel + 7) / 8; + uint32_t total_area, divisor, active_area; + uint64_t pixels_per_second, bandwidth;
divisor = 1024;